Green synthesis of benzimidazoles using Ag ۲O-Fe۳O۴ core-shell as catalyst by an electro -thermal grinding

Green chemistry has attracted a considerable importance in the development of environmentally benign routes to numerous materials. Green chemistry mainly emphasizes towards the pollution prevention through eco-friendly design of chemical products and processes. Benzimidazole and its family can be used in the energy world easily in the form of polymers, since these materials have the possibility to create designed structures for many applications. Attentive to their widespread pharmacological activity, synthesis, and application, a number of procedures have been applied for the synthesis of benzimidazole and its derivatives. Generally, the synthesis of ۲-substituted benzimidazoles involves the treatment of o-phenylenediamine either with carboxylic acids or various derivatives and the condensation of o-phenylenediamine with aldehydes in the presence of various oxidant agents. This study focuses on a novel green approach for benzimidazole synthesis using Ag ۲O-Fe۳O۴ core-shell as a heterogeneous catalyst. Magnetic nano catalysts (MNCs) in organic reactions have many advantages: i) Magnetic nanoparticles are accessible from inexpensive and non-toxic materials; ii) the stability of catalyst linkages allows the use of more environmentally friendly solvents than heterogeneous catalysis; iii) simple separation using an external magnet avoids the use of extra chemicals and additional filtration or centrifugation steps during the separation process; iv) the fabrication of MNCs is generally simple, scalable, safe, cost-effective, and controllable; v) catalyst leaching is usually lower than other material-supported catalysis. In the experimental procedure, O-phenylenediamine and benzaldehyde derivatives were combined in the presence of the Ag ۲O-Fe۳O۴ and the mixture underwent electro-thermal grinding. Reaction progress was monitored using TLC, and the final product was washed with ethanol and dried to yield crystalline benzimidazole compounds. The synthesized benzimidazole was characterized using FT-IR and ۱H NMR to confirm their structural integrity.

کلیدواژه ها:

Green chemistry ، Benzimidazoles ، Magnetic nano catalysts ، Thermal grinding